Brand new unit. Less than 90 days old. Used 6 times. Worked absolutely perfect in all modes. 7th time out surface temperature just flashes at 32degrees constantly. everything else seems to be working fine. Any brilliant ideas ? I've noticed that cleaning the transducer is widely recommended and I admit I haven't done that, but I doubt that this would be the problem. What I'm getting at is that I can't decide if something is malfuntioning within the unit display or if it's something caused by the transducer. I suppose if I send the unit back under warranty, they'll want BOTH pieces and I really hate to have to uninstall that transducer.